• How do oceans affect you? If you live far from the coast, you might think they don’t. But life on this planet depends on the oceans. They cover almost three-quarters of the planet and hold 97 percent of the Earth’s water. The phytoplankton that live on the oceans’ surface produce half of the oxygen in the atmosphere. Oceans are a vital source of food and other resources, and an economic engine for many communities.

    For all the oceans provide us, we haven’t always been so responsible in our stewardship. “The ocean was thought of as a dumping ground for so long,” says Caitlyn Toropova of the International Union for Conservation of Nature (IUCN). “There was a sense that there was no way we could harm it because it is so vast.” 

    But human activities are having a negative impact on many of the world’s oceans, jeopardizing marine life, habitat, and ecosystems. These threats include overfishing or destructive fishing, coastal development, pollution and runoff, and the introduction of non-native species. Climate change is also having a big effect by causing warming seas and ocean acidification.

    The realization that something needs to be done to stem or reverse the damage has led to the creation of marine protected areas (MPAs). Broadly speaking, a marine protected area (MPA) is a region of the ocean where human activity is limited. Specifics differ around the globe, but the United States defines a marine protected area as “any area of the marine environment that has been reserved by federal, state, tribal, territorial, or local laws or regulations to provide lasting protection for part or all of the natural and cultural resources therein.”

    There are approximately 5,000 designated MPAs around the world, but many more that are not officially recognized, says Toropova, the conservation group’s coordination officer for marine protected areas. The United States has 1,700 MPAs.

    That may sound like a lot, but less than one percent of the world’s oceans are protected. Countries around the world have committed to protecting 10 percent, Toropova says. But “even though there’s been an increase in the past 10 years, at the current rate it would take 100 years to reach that goal,” she says.

    MPA Goals

    While all MPAs are designed to limit human activity, there are different types of marine protected areas with different goals. 

    The U.S. National Oceanic and Atmospheric Administration (NOAA) developed a system that relies on a site’s five functional characteristics: conservation focus, level of protection, permanence of protection, constancy of protection, and ecological scale of protection.

    A site’s conservation focus and its level of protection are the most important characteristics. A conservation focus asks what an MPA was created to protect. It could be the water’s natural heritage—such as its biodiversity, habitat, population, or ecosystems—or its cultural heritage, which reflects the country’s maritime history and connections to the sea. Or it might have been created for sustainable production, where the focus is on managing the removal of living resources such as plants, fish, or shellfish

    A level of protection determines what kinds of activities are prohibited, restricted, or allowed in a marine protected area. Here are the varying levels of protection MPAs provide, according to NOAA’s framework:

    • Uniform multiple-use MPAs allow activities, including fishing or taking other living resources from the water, across the entire protected area.
    • Zoned multiple-use MPAs allow people to take resources, but limits where or when they can do so to lessen the impact on the area.
    • Zoned multiple-use MPAs with no-take zones are MPAs that allow many activities but have at least one zone where people are prohibited from taking any marine resources.
    • No-take MPAs or zones restrict people from taking any natural or cultural resources.


    Types of MPAs

    There are different types of marine protected areas. They may differ in their conservation focus and level of protection.

    Marine reserves are usually no-take MPAs, and therefore prohibit any taking of resources. Activities that aren’t allowed include fishing and mining. Other activities, such as swimming and boating, are often permitted. Many reserves have a strong education or research focus.

    Natural Bridges State Marine Reserve in California is one example. Located on the edge of the city of Santa Cruz, it covers 1.5 square kilometers (0.58 miles). Natural Bridges was created to protect surfgrass and sandy beach, which provide habitat for a variety of species. Fishing, drilling, and mining are not allowed at the MPA. Recreational activities like kayaking and swimming are allowed.

    Marine sanctuaries have special conservation, recreational, ecological, historical, cultural, archaeological, scientific, educational, or aesthetic qualities. Most are multiple-use areas but may be zoned with no-take areas.

    The Florida Keys National Marine Sanctuary is one of 13 U.S. sanctuaries. Located on the southern tip of Florida, it holds a wealth of natural resources, including the largest living coral reef in North America. The marine sanctuary is vast, covering 9,500 square kilometers (3,667 square miles). The rich variety of habitats includes seagrass beds and mangrove swamps. Thousands of species live in the Keys: sponges, jellies, anemones, mussels, oysters, and coral, among them.

    The sanctuary also holds cultural resources that offer a glimpse of the area’s maritime history. Since the European discovery of Florida in the 1500s, many ships have sunk in the waters off Florida. Artifacts from these shipwrecks rest in the sanctuary.

    With its natural and cultural resources, it’s not surprising the Florida Keys draws visitors: more than 4 million people each year. Commercial fishing is vital to the economy of the Keys, where more than 20 million pounds of seafood are caught annually, according to NOAA.

    The Florida Keys National Marine Sanctuary is a multiple-use MPA, with commercial, sport, and recreational fishing allowed in some zones. In other zones, only scientific research is allowed. Most of the park encourages a wide variety of recreational activities.

    National parks are large areas preserved in their natural state as public property. They are designed to protect the natural and cultural objects and wildlife within the park.

    Glacier Bay National Park and Preserve in Alaska, which covers more than 13,200 square kilometers (5,100 square miles) includes tidewater glaciers, snow-capped mountain ranges, ocean coastlines, deep fjords, and freshwater rivers and lakes. The conservation focus is on the arctic ecosystem. Commercial and recreational fishing are allowed, but limited. Sport fishermen seek Pacific halibut and different species of salmon, such as sockeye, king, and coho, in Glacier Bay. Recreational activities such as kayaking, rafting, and boat tours are allowed.

    Wildlife refuges conserve, protect, and enhance fish and wildlife and their habitats for the continuing benefit of people.

    Breton National Wildlife Refuge, in the Gulf of Mexico off Louisiana, covers about 52 square kilometers (20 square miles) and is only accessible by boat. The focus of protection is its ecosystem. One goal is to provide a haven for nearly two dozen species of birds, from nesting and wading seabirds to waterfowl and wintering shorebirds. They include endangered species like the piping plover, the least tern, and the brown pelican.

    The refuge suffered serious damage when Hurricane Katrina struck in 2005, and much of the land eroded.

    Breton National Wildlife Refuge allows recreational fishing, but commercial fishing is prohibited. Wildlife viewing is a popular recreational activity, but because so much land was lost during Katrina, camping is no longer permitted.


    Stakeholders are individuals, communities, or organizations with an interest in the marine protected area. As the above examples show, different types of MPAs provide different opportunities for stakeholders.

    The general public uses MPAs for recreation such as fishing, kayaking, sailing, boat tours, snorkeling, or wildlife viewing. There are usually few regulations on recreational activities.

    Commercial fishermen rely on the waters and the marine life in them for their livelihood. Most MPAs try to strike a balance between protecting resources and allowing for the sustainable extraction of those resources. As a result, there are very few no-take areas that prohibit all extraction. Many MPAs, however, do limit commercial fishing by where or when it can be done. Different seafood, such as salmon or lobster, have different seasons when it is safe and legal to harvest them.

    Scientists and researchers use marine protected areas to study marine life and habitats. MPAs are "living laboratories" for scientists and researchers, where they can monitor and measure the health of species, ecosystems, and human impact.

    As Toropova of the IUCN says, “Everything we depend on in life comes from the ocean.”

    Marine Protected Areas
    The Great Barrier Reef is a mixed-use marine protected area off the east coast of Australia.

    Papahanaumokuakea Marine National Monument
    Papahanaumokuakea, the area surrounding the remote and uninhabited Northwestern Hawaiian Islands, is the largest marine protected area (MPA) in the United States. The MPA is 362,072 square kilometers (139,797 square miles). Like most MPAs, it is multiple-use. The area's tuna and lobster fisheries remain open to seasonal use, while the remote islands provide protected areas for endangered species like the Hawaiian monk seal.

  • Term Part of Speech Definition Encyclopedic Entry
    aesthetics Noun

    study of beauty.

    Arctic Noun

    region at Earth's extreme north, encompassed by the Arctic Circle.

    Encyclopedic Entry: Arctic
    artifact Noun

    material remains of a culture, such as tools, clothing, or food.

    Encyclopedic Entry: Artifact
    atmosphere Noun

    layers of gases surrounding a planet or other celestial body.

    Encyclopedic Entry: atmosphere
    biodiversity Noun

    all the different kinds of living organisms within a given area.

    Encyclopedic Entry: biodiversity
    climate change Noun

    gradual changes in all the interconnected weather elements on our planet.

    Encyclopedic Entry: Earth's Changing Climate
    coast Noun

    edge of land along the sea or other large body of water.

    Encyclopedic Entry: coast
    commercial fishing Noun

    industry responsible for catching and selling fish.

    conservation Noun

    management of a natural resource to prevent exploitation, destruction, or neglect.

    Encyclopedic Entry: conservation
    conservation focus Noun

    functional characteristic of a marine protected area that outlines what an MPA was created to protect.

    coral reef Noun

    rocky ocean features made up of millions of coral skeletons.

    cultural heritage Noun

    traditions and customs of a specific population.

    development Noun

    construction or preparation of land for housing, industry, or agriculture.

    dozen Noun

    a group of 12.

    drill Verb

    to make a hole using a rotating digging tool.

    economic Adjective

    having to do with money.

    economy Noun

    system of production, distribution, and consumption of goods and services.

    ecosystem Noun

    community and interactions of living and nonliving things in an area.

    Encyclopedic Entry: ecosystem
    endangered species Noun

    organism threatened with extinction.

    Encyclopedic Entry: endangered species
    environment Noun

    conditions that surround and influence an organism or community.

    erode Verb

    to wear away.

    extract Verb

    to pull out.

    federal Adjective

    having to do with a nation's government (as opposed to local or regional government).

    fishery Noun

    industry or occupation of harvesting fish, either in the wild or through aquaculture.

    fjord Noun

    long, narrow ocean inlet between steep slopes.

    Encyclopedic Entry: fjord
    habitat Noun

    environment where an organism lives throughout the year or for shorter periods of time.

    Encyclopedic Entry: habitat
    halibut Noun

    flat fish native to the north Pacific Ocean.

    haven Noun

    safe place.

    heritage Noun

    cultural or family background.

    Hurricane Katrina Noun

    2005 storm that was one of the deadliest in U.S. history.

    jeopardize Verb

    to put in danger or threaten.

    key Noun

    small, low island on a coral reef, also known as a cay.

    Encyclopedic Entry: key
    level of protection Noun

    functional characteristic of a marine protected area that outlines what kinds of activities are prohibited, restricted, or allowed.

    mangrove swamp Noun

    coastal wetland dominated by mangrove trees, which have roots that can survive in salty water.

    marine Adjective

    having to do with the ocean.

    marine protected area (MPA) Noun

    area of the ocean where a government has placed limits on human activity.

    marine reserve Noun

    part of the ocean where no fishing, hunting, drilling, or other development is allowed.

    Encyclopedic Entry: marine reserve
    marine sanctuary Noun

    part of the ocean protected by the government to preserve its natural and cultural features while allowing people to use and enjoy it in a sustainable way.

    Encyclopedic Entry: marine sanctuary
    maritime Adjective

    having to do with the ocean.

    mining Noun

    process of extracting ore from the Earth.

    monitor Verb

    to observe and record behavior or data.

    multiple-use MPA Noun

    marine protected area that allows different levels of human activity, usually by zones.

    National Oceanic and Atmospheric Administration (NOAA) Noun

    U.S. Department of Commerce agency whose mission is to "understand and predict changes in climate, weather, oceans, and coasts; to share that knowledge and information with others, and; to conserve and manage coastal and marine ecosystems and resources."

    national park Noun

    geographic area protected by the national government of a country.

    non-native species Noun

    a type of plant or animal that is not indigenous to a particular area. Non-native species can sometimes cause economic or environmental harm as an invasive species.

    no-take zone Noun

    area set aside by the government where all extractive activity, including fishing, mining, and drilling, is not allowed.

    Encyclopedic Entry: no-take zone
    ocean Noun

    large body of salt water that covers most of the Earth.

    Encyclopedic Entry: ocean
    ocean acidification Noun

    decrease in the ocean's pH levels, caused primarily by increased carbon dioxide. Ocean acidification threatens corals and shellfish.

    overfish Verb

    to harvest aquatic life to the point where species become rare in the area.

    oxygen Noun

    chemical element with the symbol O, whose gas form is 21% of the Earth's atmosphere.

    phytoplankton Noun

    microscopic organism that lives in the ocean and can convert light energy to chemical energy through photosynthesis.

    pollution Noun

    introduction of harmful materials into the environment.

    Encyclopedic Entry: pollution
    prohibit Verb

    to disallow or prevent.

    public Adjective

    available to an entire community, not limited to paying members.

    refuge Noun

    public land set aside to protect native wildlife.

    regulation Noun

    rule or law.

    resource Noun

    available supply of materials, goods, or services. Resources can be natural or human.

    responsible Adjective

    primary cause of something.

    restrict Verb

    to limit.

    runoff Noun

    overflow of fluid from a farm or industrial factory.

    Encyclopedic Entry: runoff
    salmon Noun

    cold-water fish hunted for food and game.

    seabird Noun

    bird native to an aquatic environment.

    seafood Noun

    fish and shellfish consumed by humans.

    shellfish Noun

    any aquatic organism that has a shell or exoskeleton.

    stakeholder Noun

    person or organization that has an interest or investment in a place, situation or company.

    stewardship Noun

    responsible management to ensure benefits are passed on to future generations.

    surfgrass Noun

    plant that grows in the ocean along rocky coasts and tidepools.

    sustainable Adjective

    able to be continued at the same rate for a long period of time.

    tidewater glacier Noun

    mass of moving ice that eventually reaches the ocean.

    vast Adjective

    huge and spread out.

    vital Adjective

    necessary or very important.

    waterfowl Noun

    birds that live near the water.

    wilderness Noun

    environment that has remained essentially undisturbed by human activity.

    Encyclopedic Entry: wilderness
    wintering Adjective

    migrating to a warm climate in winter and staying until spring.